Akathisia is an odd sensation of restlessness, shakiness, and fidgeting, as if your whole body is anxious, but is usually a feeling that is hard to describe; and because akathisia is difficult to describe, it is often misdiagnosed.
Akathisia may range in intensity from a mild sense of disquiet or anxiety (which may be easily overlooked) to a total inability to sit still, accompanied by overwhelming anxiety, malaise, and severe dysphoria (manifesting as an almost indescribable sense of terror and doom).
In severe cases, Akathisia is characterized by a feeling of inner restlessness and a compelling need to be in constant motion. Severe akathisia is defined as an inability to remain still due to a sense of inner restlessness. It is like a foreign forced taking over the body and making it move constantly. People who are severely affected by akathisia fidget, are unable to sit or keep still, rock from foot to foot while standing or sitting, lift the feet as if marching on the spot, cross and uncross the legs while sitting, and pace; all of these movements are completely normal and directed at relieving an uncomfortable and severe compulsion to move. Akathisia is NOT life-threatening, but it is usually bad enough to stop the medication that causes it.
There have been a number of subtypes of akathisia proposed, although a lack of consensus in the use of the terms is still evident. Most experts refer to acute, tardive, chronic, withdrawal and pseudoakathisia, along withdiurnal variations in its expression and its common associationwith other extrapyramidal syndromes (EPS). The complex interplayof the subjective and observable components of akathisia accountfor the difficulties in differentiating it from psychoticexcitement, agitated depression and anxiety.
Acute akathisia has an onset within hours or days, however the onset may be up to six months after an increase in dosage.
Tardive akathisia is generally taken to mean akathisia of delayed onset (usually three months), not related to a recent change in drug or dose. Tardive akathisia has been found to be significantly associated with tardive dyskinesia, and some have proposed it to be a variant where the trunk and limbs are most affected. Activation procedures may help distiniguish between the two (e.g. finger tapping may increase symptoms in tardive dyskinesia but decrease the compulsion to move in akathisia).
Chronic akathisia usually refers to a persistence of akathisia symptoms for three months regardless of the type of onset. Some researchers subdivide Chronic akathisia into one that occurs early in the course of antipsychotic therapy but remains persistent, called Acute persistent akathisia, and the akathisia that occurs with long-term therapy, called Tardive akathisia; however, it is often difficult to distinguish between these two subtypes due to the often imprecise information about the timing of the onset of akathisia relative to the start of antipsychotic treatment.
Withdrawal akathisia refers to akathisia that starts within six weeks of discontinuation or a significant dose decrease.
Pseudoakathisia refers to a variant where there are objective symptoms but no subjective awareness or distress. These individuals tend to display more negative symptoms of psychotic illness.